There are 4 hidden reasons Pixar movies are so visually compelling

Danielle Feinberg's work is so good, you'd probably never even notice it.

But that's kind of the point if you're a director of photography at Pixar, where one of Feinberg's most important jobs is adding the appropriate lighting to a film. Without Feinberg's touch, films such as "Wall-E,""Brave," and "Monsters, Inc.," wouldn't be nearly as rich or complex.

Feinberg recently gave a TED talk in which she described this delicate art, and she shared with Tech Insider four key considerations that make a film magical.

1. Color

Pixar movies are not dull. They burst with color, and masterfully use each hue to tell stories.

Feinberg points to "Wall-E," a movie about a lonely robot that finds love. The movie doesn't use dialogue in the first 40 minutes of the film, so Feinberg had to find a way to communicate where Wall-E lived without words.

"We realized very quickly that if we let things go too red — the clouds, the dust, the atmosphere — it began to look like Mars," she says. "We all seem to have this ingrained notion that red equals Mars. So I had to be very careful to keep the colors of that monochromatic version of Earth in the whites, yellows, and oranges but never let it get too red."

Here are a few shots, known as progression images in lighting designer lingo, that show how the various color schemes for "Wall-E" changed over time. What begins as gray and overcast, but otherwise ordinary, ends up as a smog-filled wasteland.

The final result is clearly dystopian, but still suggests that Wall-E is living on Earth.

"Every department is helping to tell the story," Feinberg says, "but here just small changes in the color of the lighting could have ruined everything" by confusing the audience about something as basic as which planet the story is set on.

2. Nature

Unlike movies that take place on land, where creating the look of air only involves some haze or wisps of wind, creating believable underwater scenes presented a unique challenge for Feinberg while working on the 2003 film "Finding Nemo."

Feinberg had to find a way to situate audience inside Australia's Great Barrier Reef without dialing up the colors too much, in order to preserve the actual look of the ocean. One tool the team has, she says, is a light they call "murk."

"We use it to set the visibility of the water [by] decontrasting the objects as we go away from the camera, until they are the same contrast as surrounding things," Feinberg says, "so you can't make out any detail thus losing visibility and the color."

A good example of that is the scene in which Nemo and company are riding the East Australian Current (EAC) as if it were a giant underwater roller coaster.

"With the turtles riding the East Australian Current, we set the visibility of the water to be much deeper than you would ever see in real life, to help tell the story, by showing the EAC and what it is the turtles are in for their roller coaster ride," Feinberg says.

"With 'Nemo,' the lighting is not only setting up the world that is critical to the story," she adds, "but also able to set the mood without impacting the believability of the world for the audience."

3. Theme

Sometimes lighting cues can add to the tone of the overall story. Happy stories aren't set in darkness. They're bright and cheery.

In the 2012 film "Brave," Feinberg had to find a way to convey Merida's uncertainty and trepidation through the film's lighting, all while making considerations for where the story takes place.

"The lighting design I came up with for the scenes in the forest had all the light cutting off outside a little area we set up around the characters and action," she says. "The Scottish mist then hung around these dark silhouettes of trees and vegetation in the distance."

Visually, this helped calm "the busyness of the forest," but also made it easier for the audience to understand the story thematically.

"It helps with the idea that there are a lot of unknowns in that forest — magic, bears, witches," says Feinberg. "It is also the place where our main character, Merida, is figuring out who she is going to be in the world, venturing out into the great unknown of the forest and adulthood."